Coupled Modeling of Annual and Interannual Tropical Ocean-Atmosphere Interaction

项目简介项目编号：ATM-9312888项目负责人：金，飞机构：夏威夷大学项目：TOGA， CDP标题：热带海洋-大气相互作用的年际耦合模拟热带海洋-大气相互作用的研究主要集中在与厄尔尼诺-南方涛动（ENSO）现象相关的年际变率方面。为了理解、模拟和预测这一现象，已经开发了不同复杂程度的耦合模型。然而，越来越多的观测和模拟研究表明，年周期和年际变率具有内在联系。本项目将使用一系列在热带耦合模式中被证明是有用和经济的中间和混合耦合模式来研究年际和年际变率，重点是年际热带海洋-大气相互作用中年循环所起的作用。本研究的目的是提高对热带海洋-大气系统观测到的年际和年际变化的认识。中间耦合模型基于1987年Zebiak & Cane模型的简化版本，由Jin & Neelin开发并广泛分析。该模式结合了海面温度和海洋动力学的非对称分量，给出了气候年循环的真实模拟，并将用于研究年循环对年际变率的作用。频率锁定的机制，引起耦合的年和次谐波振荡将被研究。耦合的年度，准两年和低频模式将在一个广泛的参数空间范围内进行探索。中间耦合模型将得到更好的物理参数化改进，并用于进一步研究年周期和年际耦合模态的耦合动力学。本研究将在中间耦合模式研究成果的基础上，扩展到包括海洋环流模式和准稳定热带大气模式的混合耦合模式系统的研究。混合耦合模型系统允许对年际和年际节点之间的相互作用进行更复杂的检查，并利用基于中间模型的状态诊断工具探索支持准两年和低频变率的状态。

PROJECT SUMMARY PROPOSAL ID: ATM-9312888 PRINCIPAL INVESTIGATOR: Jin, Fei-fei INSTITUTION: University of Hawaii PROGRAM: TOGA, CDP TITLE: Coupled Modeling of Annual and Interannual Tropical Ocean- Atmosphere Interaction Investigations of the tropical ocean-atmosphere interaction have focused largely on aspects of the interannual variability related to the El Nino-Southern Oscillation (ENSO) phenomenon. Coupled models of differing complexity have been developed to understand, simulate, and predict this phenomenon. However, there are increasing indications from both observational and modeling studies that the annual cycle and interannual variability are intrinsically related. This project will use a series of intermediate and hybrid coupled models, proven to be useful and economical in tropical coupled modeling, to investigate annual and interannual variability with an emphasis on the role played by the annual cycle in the interannual tropical ocean-atmosphere interaction. The goal of this research is improved understanding of the annual and interannual variabilities observed in the tropical ocean-atmosphere system. The intermediate coupled model, based on a simplified version of the 1987 Zebiak & Cane model, has been developed and extensively analyzed by Jin & Neelin. This model incorporates asymmetric components of sea surface temperature and ocean dynamics to give a realistic simulation of the climatological annual cycle and will be used to investigate the role of the annual cycle on the interannual variability. The mechanisms of frequency locking that give rise to coupled annual and sub-harmonic oscillations will be investigated. The regimes of coupled annual, quasi-biennial and low-frequency modes will be explored in an extensive range of parameter space. The intermediate coupled model will be improved with better parameterization of the physics and used fo r further studies of the coupled dynamics of the annual cycle and the interannual coupled modes. This investigation will be extended, based on the results from the research with the intermediate coupled model, to studies with a hybrid coupled model system which includes an ocean general circulation model and a quasi-steady tropical atmosphere model. The hybrid coupled model system permits a more sophisticated examination of the interaction between annual and interannual nodes and an exploration of the regime which supports the quasi-biennial and low-frequency variability with a regime diagnostic tool based on the intermediate model.